Imaging spectrometers that form high-resolution images in a wide range of spectral bands are used in scientific, military, and resource-sensing applications. Such spectrometers provide an image and also a spectral analysis of the image in a selected wavelength band. However, the existing designs have limitations on the wavelengths that may be analyzed. In developing the present invention, the inventor has observed that in some applications it would be useful to simultaneously assess the image in two spectral bands that are disjoint and well separated. For example, the reflective/emissive spectral band of 0.5-5 micrometers wavelength yields visible and mid-infrared information, and the long wavelength infrared band of 7.5-12.5 micrometers yields thermal information. These two types of information, taken together and possibly with a broad band visible-light image, allow analysis of the features of the scene not possible with existing imaging spectrometers.
The existing designs of imaging spectrometers do not permit hyperspectral imaging in two different disjoint, well-separated spectral bands such as those discussed. There is a need for such a capability. The present invention fulfills this need, and further provides related advantages.